Ebook FRCR 2B Viva-A case-based approach: Part 1

(BQ) Part 1 book FRCR 2B Viva-A case-based approach presents the following contents: Gastrointestinal imaging, chest imaging, musculoskeletal imaging. Invite you to consult.

Trang 1

A Case-Based Approach

Paul S Sidhu

Suzanne M Ryan

Phillip F C Lung

Trang 2

FRCR 2B Viva:

A Case-Based Approach

Paul S Sidhu, BSc (Hons.), MBBS (Hons.), MRCP, FRCR, DTM&H

Professor of Imaging Sciences

King’s College London

Consultant Radiologist

King’s College Hospital

Denmark Hill, London

United Kingdom

Suzanne M Ryan, MRCPI, FRCR

Consultant Gastrointestinal and Abdominal Radiologist

United Kingdom

Phillip F C Lung, BSc (Hons.), MBBS, MRCS, FRCR

Subspeciality Fellow in Gastrointestinal Radiology

Trang 3

therapy Insofar as this book mentions any dosage or application, readers may rest assured that the authors, editors, and publishers have made every eﬀ ort to ensure

that such references are in accordance with the state of

knowledge at the time of production of the book.

Nevertheless, this does not involve, imply, or express any guarantee or responsibility on the part of the publishers in respect to any dosage instructions and forms of applications

stated in the book Every user is requested to examine

carefully the manufacturers' leafl ets accompanying each

drug and to check, if necessary in consultation with a cian or specialist, whether the dosage schedules mentioned therein or the contraindications stated by the manufacturers diﬀ er from the statements made in the present book Such examination is particularly important with drugs that are either rarely used or have been newly released on the market Every dosage schedule or every form of application used is entirely at the user’s owwn risk and responsibility The authors and publishers request every user to report to the publishers any discrepancies or inaccuracies noticed If errors in this work are found after publication, errata will be posted at www.thieme.com on the product description page

Rüdigerstrasse 14, 70469 Stuttgart, Germany

http://www.thieme.de

Thieme Medical Publishers, Inc., 333 Seventh Avenue,

New York, NY 10001, USA

http://www.thieme.com

Cover design: Thieme Publishing Group

Printed in Germany by AZ Druck, Kempten

ISBN 978-3-13-166291-0

eISBN 978-3-13-166361-0

Some of the product names, patents, and registered designs referred to in this book are in fact registered trademarks or proprietary names even though specifi c reference to this fact

is not always made in the text Therefore, the appearance of

a name without designation as proprietary is not to be strued as a representation by the publisher that it is in the public domain

con-This book, including all parts thereof, is legally protected by copyright Any use, exploitation, or commercialisation outside the narrow limits set by copyright legislation, without the publisher’s consent, is illegal and liable to prosecution This applies in particular to photostat reproduction, copying, mimeographing, preparation of microfi lms, and electronic data processing and storage

Trang 4

Thanks must go to my wife, Monica, and children, Francesca and Gianluca, for their remarkable tolerance.

Trang 5

Section 1: Gastrointestinal Imaging

Phillip F C Lung, BSc (Hons.),

MBBS, MRCS, FRCR

Subspeciality Fellow in Gastrointestinal Radiology

Department of Radiology

United Kingdom

Suzanne M Ryan, MRCPI, FRCR

Consultant Gastrointestinal and Abdominal

Radiologist

United Kingdom

Section 2: Chest Imaging

Joseph Jacob, BSc, MBBS (Hons.),

MRCP, MRCS, FRCR, DTM&H

Specialist Registrar in Radiology

United Kingdom

Sujal Desai, MBBS (Hons.),

MD, FRCP, FRCR

Senior Lecturer

King‘s College London

Consultant Thoracic Radiologist

King‘s College Hospital

United Kingdom

Section 3: Musculoskeletal Imaging

Ounali S Jaﬀ er, MBBS, MRCP, FRCR

United Kingdom

Imran Khan, MBBS, MRCS, FRCR

Specialist Registrar in RadiologyDepartment of RadiologyKing’s College HospitalDenmark Hill, LondonUnited Kingdom

Section 4: Neurological Imaging Aarti Shah, MA, BM, BCh, MRCP, FRCR

Nagachandar Kandasamy, MBBS, DMRD, FRCR

Consultant NeuroradiologistDepartment of NeuroradiologyKing’s College HospitalDenmark Hill, LondonUnited Kingdom

Section 5: Urogynaecological Imaging Diana Bosanac, MBBS, FRCR

Dean Huang, BMedSci, BMBS, MRCPCH, FRCR, EBIR

Consultant Radiologist in Genitourinary and Interventional Radiology

Department of RadiologyKing’s College HospitalDenmark Hill, LondonUnited Kingdom

Trang 6

Nicola Mulholland, MBBS, MSc, MA (Cantab), FRCR, FRCP

Consultant Radiologist and Nuclear Medicine PhysicianDepartment of Radiology

King’s College HospitalDenmark Hill, LondonUnited Kingdom

Section 6: Paediatric Imaging

Preena Patel, BSc, MBBS, FRCR

United Kingdom

Maria E K Sellars, MBBS, FRCR

Consultant Paediatric Radiologist

United Kingdom

Trang 7

This book is an excellent collection of cases ideal for

the preparation of FRCR 2B Viva examinations There

is a great variety of cases with a wonderful section

on tips for candidates appearing for the

examina-tion This has been constructed from a continuum of

knowledge gained over three decades from

consul-tants who have experience of examining candidates

and specialist registrars who have passed the

exami-nation The cases span the spectrum of diseases

com-monly brought to the examination by generations of

examiners When I read the book it became obvious

that it is a vital link in the teaching portfolio because

it demonstrates how to approach each case, pick

up the radiological signs, and formulate an answer

There are notes related to the disease and a short bibliography The contents cover gastrointestinal, chest, musculoskeletal, neuroradiology, urogynae-cological, paediatrics, and radionuclide imaging This book is modern, up to date, and is based on organ imaging I believe it will also prove to be an excellent revision book that will not become obsolete and is well worth owning

Professor Philip Gishen, MB, BCh, DMRD, FRCR

Imperial College Healthcare NHS Trust

Trang 8

allow the candidate to achieve this; we have detailed the best approach to an image, and the response to further questions, in a manner that is succinct and clearly responds to the situation Each case has a model answer, with all the relevant background information needed to confi dently assess and detail

an appropriate explanation of a fi lm The cases sented are classics in each section; the answers are models to build on; the background knowledge and bibliography are to be read and understood

pre-Each section is authored by a specialist registrar who has recently passed the FRCR 2B examination, supervised by an experienced consultant with a sub-specialty interest, all of whom have at some time been teachers on the King’s College Hospital FRCR 2B course To this eﬀ ect, we believe we have produ-ced an ideal approach to assimilating the response desired by the examiner and providing success in the examination

Paul S Sidhu Suzanne M Ryan Phillip F C Lung

There are several Fellowship of the Royal College

of Radiologists (FRCR) Part 2B examination books

on the market at present, detailing cases in a

man-ner that will test the candidate These books are of

course an invaluable source of information and allow

for self-testing Here, we have designed a book for the

FRCR 2B Viva examination not to test the candidate’s

knowledge, but to demonstrate the approach to the

case and formulation of the ideal answer The

pur-pose of this book is not to test but to allow

construc-tion of the most suitable response in the examinaconstruc-tion

The vast majority of candidates for the FRCR 2B

examination are well prepared, with an extensive

and comprehensive knowledge of the subject The

expression of this knowledge in the formal setting

of the examination may, however, be a problem for

some of the candidates There is no point in

kno-wing everything if you cannot demonstrate this to

the examiner Our aim is to establish a formula to

Preface

Trang 9

As with any book, a large number of people make contributions, which are often unacknowledged in the fi nal manuscript Without their contributions, success would not have been possible, particularly with a book like this that requires many teaching cases We wish to thank the entire Department of Radiology at King’s College Hospital, London.

Paul S Sidhu Suzanne M Ryan Phillip F C Lung

Trang 10

2.1 Anterior Mediastinal Mass 44

2.2 Sickle Cell Disease 46

2.13 Posterior Mediastinal Mass 68

2.14 Langerhans’ Cell Histiocytosis 70

2.15 Pneumocystis jirovecii Pneumonia 72

2.16 Lobar Collapse 74

2.17 Lung Cancer 76

2.18 Lung Collapse Caused by a Saccular

Aneurysm 78

2.19 Anomalous Right Coronary Artery 80

2.20 Cannonball Secondaries from

Dihydrate Deposition Disease and Haemochromatosis 110 3.12 Geode 112 3.13 Paget’s Disease 114 3.14 Transient Lateral Patellar

Dislocation 116 3.15 Polyostotic Fibrous Dysplasia 118 3.16 Lisfranc Injury 120 3.17 Sarcoidosis 122

3.19 Cervical Instability in Rheumatoid Arthritis 128 3.20 Pigmented Villonodular Synovitis 130

4 Neurological Imaging 134

4.1 Sturge–Weber Syndrome 136 4.2 Multiple Sclerosis 138 4.3 Tuberous Sclerosis 140 4.4 Acute Cerebral Infarction 142 4.5 Glioblastoma 146 4.6 Toxoplasmosis 148 4.7 Herpes Simplex Virus

Encephalitis 150 4.8 Pituitary Fossa Mass 152 4.9 Cavernoma 154 4.10 Meningioma 156 4.11 Chiari Malformation 158 4.12 Subarachnoid Haemorrhage 160 4.13 Subdural Empyema 162 4.14 Medulloblastoma 164 4.15 Ruptured Dermoid 166 4.16 Von Hippel–Lindau Syndrome 168 4.17 Cerebellopontine Angle Mass 170 4.18 Neurocysticercosis 172

Contents

Trang 11

6.6 Hirschsprung’s Disease 234 6.7 Intussusception 236 6.8 Malrotation 238 6.9 Meconium Aspiration Syndrome 240 6.10 Necrotising Enterocolitis 242 6.11 Osteogenesis Imperfecta 244 6.12 Osteomyelitis 246 6.13 Osteosarcoma 248 6.14 Perthes Disease 250 6.15 Respiratory Distress Syndrome 252 6.16 Sequestration 254 6.17 Slipped Upper Femoral Epiphysis 256 6.18 Wilms’ Tumour 258 6.19 Developmental Dysplasia of the Hip 260 6.20 Neuroblastoma 262

7 Radionuclide Imaging 264

7.1 Cold Spot 266 7.2 Gastrointestinal Bleeding 268 7.3 Hypertrophic Osteoarthropathy 270 7.4 Malignant “Super Scan” 272 7.5 Meckel’s Diverticulum 274 7.6 Carcinoid Tumour 276 7.7 Osteomalacia 278 7.8 Paget’s Disease 280 7.9 Parathyroid Adenoma 282 7.10 Pulmonary Embolism 284 7.11 Phaeochromocytoma 286 7.12 Pelviureteric Junction Obstruction 288 7.13 Renal Laceration 290 7.14 Spondylolysis 292 7.15 Autonomous Toxic Thyroid Nodule 294

Index 297

4.19 Spontaneous Intracranial

Haemorrhage 174 4.20 Traumatic Brain Injury 176

6.4 Congenital Lobar Emphysema 230

6.5 Hepatoblastoma 232

Trang 12

own responsibility If the hours of work and mulation of knowledge have not been achieved, the candidate will not pass the examination Nobody can teach this; this is an attitude that should be acqui-red from early in the candidate’s career Poor know-ledge is very quickly spotted by the examiner Do not blame others in your department for your failure—it

accu-is your responsibility to seek out, acquire, and solidate knowledge Teaching guides and directs you

con-to the correct manner in which con-to use the knowledge you acquire by reading and experience

Nevertheless, even the most prepared candidate will be

a nervous wreck on examination day The ability to cess the knowledge and formulate an intelligent answer needs to be implicit—this is the “game.” The game is not won without knowledge, but the presentation of the self-acquired knowledge in a meaningful manner can be taught This is where pre-examination teaching

pro-is important; sit with your senior colleagues and tise the viva technique Never go into an examination without being fully prepared as you will not succeed

prac-Candidates need to have a rigid formula to present their knowledge in a manner that cannot be faulted

The Examiner Spare a thought for this poor soul—

unpaid, unloved, and subject to 5 or more gruelling days of listening to anxious, nervous individuals who are often incoherent, all in a room 6 foot (or less) square, with no natural light If this sounds cruel, it is, but the examiners keep coming back The examiner has previously been a candidate and will understand the anxiety The examiner will not only be knowledgeable, but most importantly will know exactly what is on the

fi lm being shown and will know the fi nal diagnosis

The candidate will not This is often the only diﬀ ating factor between candidate and examiner, as often the breadth of knowledge is greater in the candidate

erenti-The examiner is not out to fail the candidate All the examiners are selected and trained to be decent, respectable examiners; they will do their utmost to settle the candidate, tease out knowledge, and try to get the candidate through the examination No exa-miner will lead the candidate in the wrong direction

or try to humiliate the candidate But if candidates have poor knowledge, they will not succeed

A medical career is littered with numerous

examina-tions, a necessity for climbing further up the ladder

of specialisation and for the eventual attainment of a

goal, in this case attainment of a postgraduate qualifi

-cation and career in radiology Very few people enjoy

an examination, particularly an examination that

involves “face-to-face” confrontation with two

ners; the “viva voce” beloved by purveyors of

exami-nations However, there is no substitute for this type

of examination, stressful as it is for the candidate; the

viva examination has from time immemorial been the

best method of assessing skills of processing

informa-tion and formulating an opinion It is here to stay

The candidate for the FRCR 2B examination is

sub-ject to a viva and will need to be fully prepared for

this process There is no reason why the candidate

should be anything but fully confi dent in this process

and be ultimately successful But candidates will not

pass the examination if they have not put in years

of toil, reviewing all manner of images and building

up a “databank” of knowledge There is no substitute

for hard work Examinations are also a game, played

out to achieve a result Play the game right and you

will pass Once the knowledge has been attained

by candidates, displaying all they have learned in a

meaningful manner is the winning game

A breakdown of the components will give a better

understanding of the process

The Candidate After many years as a medical

stu-dent, postqualifi cation ward work, and often 3 years

of basic grounding in radiology, the examination

is tackled At this stage, the candidate should have

reviewed thousands of “examination” style fi lms,

in all imaging modalities, and have read around the

subject every time a new disease or abnormality is

encountered Very often the presentation of a disease

process is faced while “on call,” when there is

pres-sure to come to a diagnosis, a process that will

rein-force any knowledge gained—do not underestimate

the importance of emergency work

The entire working life of a candidate up to the

exa-mination is a learning process, and the ability or

desire to accumulate knowledge is the candidate’s

Introduction to the FRCR 2B Viva

Trang 13

it correct, you have passed Normally, there is plenty

of time to show many cases Never argue with the examiner, as it will get you nowhere and you will be likely to fail All the fi lms are vetted before the exami-nation, and there are no fi lms that are “‘wrong”—you

do not have more insight than the panel of ners If the examiner tells you something that you disagree with, move on with the case or move to the next case At the end of the examination, thank both examiners in a brief and professional manner There

exami-is no place for a hug if you think you have done well

After the Examination There is a gap between the

end of the examinations and the availability of the results; this is the time to “brag.” Every candidate has been shown the worse possible combination of “sne-aky” fi lms designed to “trip up” innocent candidates and fail them outright Nevertheless, the candidate, with incredible foresight and intelligence, has spotted this trap set by the evil examiners, designed to foil career progression, and spun out an incredible answer that could not be faulted, has undoubtedly shown the examiners to be clowns, and has secured a pass It was even said that the President of the College had heard about this incredible candidate and had asked to perso-nally meet to oﬀ er congratulations; a standing ovation among the examiners would precede this meeting

It is true that candidates pass because they are good enough—candidates fail because they were not good enough The tendency is often to dwell on the

“missed” aspects of the fi lms and forget the correct diagnosis made This is a natural tendency, and it is best to wait for the result rather than agonise over the possibilities Discussion after the examination is good for all; it lets oﬀ all that accumulated anxiety,

so do it and embellish all you like as it does no harm

So, in summary:

1 Knowledge is gained only by hard work

2 Teaching is desirable but is no substitute for ding and working

rea-3 A well-prepared candidate will not fail

4 Teaching of examination technique is mandatory prior to the examination

5 The examiners are not out to fail the candidate—lack of knowledge is easily evident

6 Think before you speak in the examination—you cannot retract what you have said

The ability to formulate a suitable response forms the basis of the chapters of this book

Paul S Sidhu

Two examiners are present, and both will assess the

candidate and each other—if one examiner has been

harsh in judging the candidate, the other will note

this The examiners are not out to fail a candidate—

candidates fail because they were not good enough

The examiners have homes, families, and work places

to go to after the examination period is over; they

will be courteous and fair to all the candidates and

will not single anyone out for “rough” treatment The

capability of the candidate is usually obvious at the

end of the viva, as is whether the candidate has been

successful Rarely is a candidate subject to a review

at the end of the process and there is disagreement

The Examination Confi ned in the small room are

two examiners and a candidate, so pay attention to

your personal hygiene Dress in a presentable and

nonprovocative manner Be pleasant but not overly

friendly; do not address the examiners by their fi rst

name Do not rush to the examination hall but arrive

with plenty of time to spare Sit and have a cup of

tea or coﬀ ee with colleagues, and go to the bathroom

before the viva! Do not try to learn something new

before going into the examination, as this is a waste

of time and will push up your state of anxiety

The examiner is likely to start oﬀ with a simple and

straightforward fi lm to ease you into the examination

and to calm you down You will not be given the

“prize-winning” set of fi lms of the rarest case for your fi rst set

of examination questions Look at the fi lm carefully,

look at review areas, and think about the fi lm If you

have worked hard, listened to your senior colleagues,

read around the subject, been “on call,” you will have

encountered a similar fi lm in the past Do not blurt

out an answer you cannot retract Count to 5, and

then describe what you see Give the diagnosis if it is

an “Aunt Minnie” (often this will be the case with the

fi rst fi lm) and wait for the examiner to reply This is

not a dinner party or social occasion where you as the

host need to keep a conversation going Shut up when

there is nothing more to say and let the examiner take

you on to the next stage with a question If you are

correct, the fi lm will be removed; if more is needed,

a question will be asked The examiner not involved

in asking questions is the one doing the marking No

examiner is supposed to show fi lms in their own

sub-specialty, and the other examiner will note this

The number of fi lms viewed in the course of the

examination is no indication of your success: if you

have reviewed only one complex case and have got

Trang 14

1 Introduction to Gastrointestinal Imaging

Good knowledge and understanding of gastrointestinal

imaging is essential for success at radiological

exami-nations However, this can be diﬃ cult at a time when

fl uoroscopic techniques are on the wane and use of

MRI on the rise; examinees are caught in the middle

of changing clinical practice Examiners tend to display

barium studies (prized fi lms kept as important teaching

examples) that many candidates may not have

experi-enced outside of educational examination courses

While there is no substitute for experience, there are

pointers that may make the interpretation easier

1 Plain abdominal fi lms may be diﬃ cult to read, but

can be broken down into “bite-size” chunks:

• Bowel The study has usually been performed

to look at the bowel, in particular the bowel gas

pattern Unless there is an obvious abnormality

elsewhere that immediately catches your eye,

you should fi rst assess the bowel; gaseous

dis-tension, constipation, absence of gas,

dilata-tion, and abnormal wall are all important

• Intra-abdominal free gas This should be

exclu-ded in all fi lms in spite of whatever clinical

details you have Rigler’s sign and

retroperito-neal free gas outlining the kidney must be

spe-cifi cally checked for

• Solid organs Are they enlarged or atrophic?

Is there any associated calcifi cation? Are they

outlined by gas? Is there any gas within the

structure (biliary or portal venous in the liver,

gas within the bladder)?

• Bone and joint degenerative disease is

com-mon, and bony destruction from tumour may

be a pointer to the reason the fi lm was shown

• Review areas Look at the lung bases and

her-nial orifi ces

2 Be methodical and you will pick up the vast

majo-rity of lesions Diﬃ cult fi lms are there to identify

candidates who are not methodical

3 Barium studies remain a staple of the examination,

despite the fact that fewer such examinations take

place in routine clinical practice As a result, it is

unlikely that the candidate will be shown a subtle

case, but the candidate should have good

know-ledge of the following types of cases:

• Cancers of any part of the gastrointestinal tract

must be searched for and excluded

• Emergencies include volvulus and megacolon

• Infl ammatory bowel disease: Always look out for gallstones, sacroiliitis, and malignancy

• Target lesions may be subtle and multiple

• Changes may be seen in the overall fold tern, as in coeliac disease and scleroderma

pat-• “Aunt Minnies”: Achalasia, candidiasis, linitis plastica, and so on may all occur

4 Take your time to look at all of the opacifi ed lumen

Always check the background chest or abdomen,

as well as the bones At the end of every review of

a barium study, you must say that you would like

to view the entire series as an important detail may be on a view that you have not yet seen

5 CT and MRI are currently viewed on hard copies in

the viva As a result, there will be multiple images

on each fi lm, and the technique for viewing these

is diﬀ erent from that of scrolling on a computer

This will alter in due course, with based examinations being introduced; however, accumulation of suﬃ cient examination cases will take time

computer-• Have a quick look at the fi lm to see if an ous abnormality is apparent Use the clinical information that is available to direct this

obvi-• If no overt abnormality is seen on the initial survey, concentrate on a single organ before moving to another organ This will allow you to build up a picture and exclude abnormalities as you progress If you try to look at every organ

on one image before moving to another one, you will spend overall more time and may miss details

• There will often be several abnormalities on the

fi lm, and you need to pick them all up Once you have picked up one abnormality, think about the clinical context to direct your search For example, if the liver looks cirrhotic, make sure you exclude hepatocellular carcinoma, and look for portal vein thrombosis, varices, and ascites

6 All your cases should end by discussing the

management options Try to remember what you

do at your institution Local multidisciplinary nical meetings are the ideal environment to pick

cli-up these details In your preparation, you should always know what the management is for any particular case If you do not know, ask

Phillip F C Lung and Suzanne M Ryan

Trang 15

Clinical History

A 42-year-old woman presents with a history of

dys-phagia (Fig 1.1.1).

Ideal Summary

This is a frontal chest radiograph of a woman There

is a double right cardiac contour with a right

para-vertebral opacity that extends below the level of the

hemidiaphragm (Fig 1.1.1, arrow) No air–fl uid level

is seen There is no bony destruction or loss of disc

space in the adjacent thoracic spine The lungs and

pleural spaces are clear The hila appear

unremar-kable, and the aortic knuckle is to the left of the

mid-line I would like to comp are this with any previous

fi lms Given the clinical history, the opacity is most

likely due to a dilated oesophagus Causes for this

include achalasia and malignancy I would confi rm

this with a barium swallow examination

These are two images from a barium study on the same

patient (Fig 1.1.2).

These are selected images from a contrast swallow study

A grossly distended oesophagus is seen overlying the

mediastinum There is a transition point in the region of

the gastro-oesophageal junction (Fig 1.1.2, arrow) with

smooth narrowing into a “bird’s beak” (also known as a

“rat’s tail”) Contrast is seen distally within the stomach

No mucosal abnormalities are identifi ed I would like

to review the remainder of the series The most likely

diagnosis is achalasia, and I would recommend that this

patient be referred to the gastroenterology team

Comment on the outline of the oesophagus

• If it is smooth, consider achalasia

• If there is focal irregularity, consider geal malignancy

oesopha-• If diﬀ use irregularity is present, candidiasis may produce oesophageal dilatation with aperistalsis Always check the stomach as primary gastric carcinoma with gastro-oesophageal stricture may produce a similar appearance

Comment on the gastro-oesophageal junction If

it is patulous, this may be from scleroderma or drugs; if it is narrowed, this may indicate acha-lasia, malignancy, postinfl ammatory or extrinsic compression

Look at the lung fi elds for evidence of aspiration

Diﬀ erential Diagnosis

The imaging appearances shown in Fig 1.1.2 are

classic for achalasia However, important diﬀ erential diagnoses to consider in a case of oesophageal narro-wing include:

Oesophageal malignancy:

• There is likely to be an irregular contour of the distal oesophagus with possible shouldering present

Fig 1.1.2

Trang 16

The oesophageal dilatation in secondary achalasia (< 4 cm) is typically less than that found in pri-mary achalasia (> 4 cm) The narrowing of the distal oesophagus in secondary achalasia may be irregular, refl ecting the underlying cause.

Primary peristalsis is absent in classic achalasia

There is an increased risk of squamous cell noma of the order of 2 to 7%

carci-Bibliography

Cole TJ, Turner MA Manifestations of gastrointestinal disease on chest radiographs Radiographics 1993;13(5):1013–1034Jang KM, Lee KS, Lee SJ, et al The spectrum of benign esophageal lesions: imaging fi ndings Korean J Radiol 2002;3(3):199–210

• The narrowed distal segment may produce a

rat’s tail appearance

• It may occasionally produce imaging fi ndings

similar to those of achalasia with a smooth

symmetrical narrowing and aperistaltic

dila-ted proximal oesophagus

Infl ammatory stricture at the gastro-oesophageal

junction:

• Typically, there is smooth narrowing of a short

segment of distal oesophagus

• Peristalsis is maintained, and the degree of

oesophageal dilatation is less than that found

in achalasia

• Ulcers and thickened mucosal folds may

sug-gest an infl ammatory component

Notes

Achalasia is a motility disorder with failure of

relaxation of the lower oesophageal sphincter

Trang 17

centrally (Fig 1.2.2, arrow) and posterior acoustic

shadowing that may represent an appendicolith or gas There is thickening of the appendix wall, with a combined wall thickness greater than 7 mm in dia-meter (0.81 cm between the callipers) No free fl uid

is seen The imaging fi ndings are in keeping with acute appendicitis, and I would urgently refer the patient to the surgical team for consideration for an appendicectomy

These are further images from the same patient; a CT examination was performed (Figs 1.2.3 and 1.2.4).

These are selected axial images of a contrast-enhanced

CT examination There is a calcifi ed appendicolith (Fig 1.2.3, arrow) seen at the base of the appen-

dix, and the appendix itself is distended with fl uid

A 23-year-old man presents with right-sided

abdomi-nal pain (Fig 1.2.1).

Ideal Summary

This is a plain fi lm abdominal radiograph of an

adult Two calcifi c densities can be seen in the right

hemipelvis (Fig 1.2.1, arrow) They do not have the

central lucency typical of phleboliths There are no

dilated bowel loops or any evidence of free

intrape-ritoneal gas The appearances are nonspecifi c, but,

given the clinical history, an important diﬀ erential

diagnosis to consider would be an appendicolith I

would perform an ultrasound examination to assess

the right iliac fossa to see if an abnormal appendix

could be identifi ed

These are two images from the ultrasound examination

on the same patient (Fig 1.2.2).

These are ultrasound images of a blind-ending

viscus, likely the appendix, with high refl ectivity

Fig 1.2.1

Fig 1.2.3 Fig 1.2.2

Trang 18

1.2 Acute Appendicitis

(Fig 1.2.4, arrow) There is fat stranding around the

appendix with free fl uid in the pelvis There is no

evi-dence of a mass at the appendix level or free gas to

suggest a perforation

Examination Tips

If you are shown a case of appendicitis, be aware of

the specifi c fi ndings within and the limitations of

• An appendiceal mass may displace bowel loops

away from it and appear as an ill-defi ned area

of increased density

Ultrasound:

• The appendix should be seen as blind-ending and arising from the caecum It is best seen using a high-frequency linear transducer, espe-cially in children

• An appendicolith may be seen as nal high refl ectivity with posterior acoustic shadowing, although gas may produce a similar

intralumi-fi nding

• An infl amed appendix is noncompressible, with a combined wall thickness measuring greater than 7 mm; associated free fl uid may also be seen

CT scanning:

• Fat stranding and free fl uid are often the fi rst clues to locating the abnormality

• Always check for adjacent extraluminal free gas

In a patient with the features demonstrated above,

no diﬀ erential diagnoses need to be oﬀ ered

Notes

Classic clinical symptoms are periumbilical pain moving to the right iliac fossa However, atypical signs are seen in one-third of patients

Around 95% of patients with acute appendicitis have a raised white blood cell count

Bibliography

Gaitini D Imaging acute appendicitis: state of the art J Clin Imaging Sci 2011;1:49

Fig 1.2.4

Trang 19

patient for liver metastases and also look for a ble primary tumour in the bowel.

possi-Here is further imaging performed on the patient

(Fig 1.3.3).

This is an octreotide nuclear medicine study taken at

24 hours Several focal areas of increased uptake are seen within the centre of the abdomen, corresponding

to the mesenteric mass seen on the CT examination A smaller focus of increased uptake is seen within the anterior liver No other sites of abnormal increased uptake are seen The fi ndings are consistent with a mesenteric carcinoid tumour and liver metastasis I would like to assess the liver on a biphasic CT

When dealing with a mesenteric mass, comment on the following:

Is the lesion well-defi ned or irregular?

Is there spiculation to suggest a desmoplastic reaction?

When multiple mesenteric masses are present, necrotic change is more in keeping with infection with tuberculosis

Calcifi cation may represent treated disease and may be either lymphoma or tuberculosis

Look for complications associated with a carcinoid tumour:

• Tethered small bowel loops, which may cause adhesional small bowel obstruction

• Small bowel ischaemia related to mesenteric vessel infi ltration

• Intussusception with a carcinoid tumour as the lead-point

There is no diﬀ erential diagnosis for the above imaging appearances

A 55-year-old man presents with a history of watery

diarrhoea (Figs 1.3.1 and 1.3.2).

Ideal Summary

These are axial CT images through the abdomen with

intravenous contrast enhancement There is a

spicu-lated soft tissue mass, lying centrally, seen within the

mesentery and containing focal areas of calcifi cation

(Fig 1.3.1, arrow) A desmoplastic reaction is centred

on the mesenteric soft tissue (Fig 1.3.2, arrow) with

tethering of several small bowel loops The bowel

appears unremarkable Hazy fat stranding of the

adjacent mesentery is also present The most likely

diagnosis is a carcinoid tumour Given the clinical

history, I would like to examine the liver to assess the

Fig 1.3.1

Fig 1.3.2

Trang 20

1.3 Carcinoid Tumour

Patients with carcinoid tumours are most

com-monly asymptomatic

Carcinoid syndrome occurs in 10% of patients, in

the presence of liver metastases, and the patient

may experience fl ushing, watery diarrhoea, and

bronchial constriction

Carcinoid syndrome is associated with cardiac

abnormalities in two-thirds of patients, including

pulmonary/tricuspid stenosis or regurgitation;

there may be right heart enlargement

A total of 30% of carcinoid tumours are multiple

The primary gastrointestinal carcinoid tumour

is submucosal, and a barium follow-through

examination was historically used to detect

this, although this was associated with a poor

sensitivity when the primary was less than

2 cm in size

• Carcinoid tumours may appear as smooth

int-raluminal defects and may appear as a “target”

lesion if there is ulceration

• There may be thickening of the mucosal folds

caused by the primary tumour

• With mesenteric involvement and a plastic reaction, there may be tethering and angulation of the small bowel loops

A small bowel carcinoid tumour is better depicted

on triphasic CT enterography with negative (or neutral) oral contrast, as the submucosal masses are highly vascular

Liver metastases are also highly vascular and must

be assessed on both arterial and portovenous phase CT imaging

Iodine 131-MIBG may be used to detect endocrine tumours such as carcinoid tumours, pheochromocytoma, and neuroblastoma

Indium 111-octreotide has a sensitivity of 75%

and a specifi city of 100% in the detection of carcinoid tumours

Bibliography

Horton KM, Kamel I, Hofmann L, Fishman EK Carcinoid tumors of the small bowel: a multitechnique imaging approach AJR Am J Roentgenol 2004;182(3): 559–567

Fig 1.3.3

Trang 21

a portal vein thrombus The spleen appears ged, but I would like to see a coronal reformat to confi rm this A small volume of ascites is present

enlar-in a perihepatic distribution I can see no evidence

of variceal formation The features are in keeping with decompensated liver cirrhosis with portal vein thrombosis I would refer the patient to the hepato-logists for further management

a recognised complication Portal vein thrombus: also look for a portal vein cavernoma following thrombosis

Sequelae of portal vein hypertension:

• Left gastric and oesophageal varices; nalisation of the umbilical vein within the falciform ligament; venous collaterals in the anterior abdominal wall

reca-• Mesenteric oedema due to raised venous pressure

• Splenomegaly The presence of ascites, which is suggestive of liver function compromise and decompensation

There is no diﬀ erential diagnosis for the above ging appearances

ima-Notes

The liver margin may be smooth, nodular, or lobular; however, this does not correspond to the underlying cause of the cirrhosis

The presence of a mass, focal increased arterial enhancement, with portal venous washout and arterio-portal shunt are all suggestive of a hepato-cellular carcinoma

A 54-year-old man presents with a history of

abdomi-nal pain (Figs 1.4.1 and 1.4.2).

Ideal Summary

These are selected axial portal venous phase

ima-ges through the upper abdomen The contour of the

liver is irregular throughout, and the parenchyma

is heterogeneous, but there are no focal

intrahe-patic lesions I can see a fi lling defect within the

main portal vein (Fig 1.4.2, arrow) in keeping with

Fig 1.4.1

Fig 1.4.2

Trang 22

1.4 Cirrhosis

A transjugular intrahepatic portosystemic

stent-shunt will divert fl ow from the portal venous

circulation and into the hepatic vein This will

improve portal hypertension and has a role in the

treatment of variceal bleeding

Bibliography

Brancatelli G, Federle MP, Ambrosini R, et al Cirrhosis:

CT and MR imaging evaluation Eur J Radiol 2007;

61(1):57–69

Trang 23

Fig 1.5.1

Fig 1.5.2

Fig 1.5.3

arrow), which exhibits a “saddle- shape” morphology

on the three-dimensional image (Fig 1.5.4, arrow)

I cannot see any soft tissue extending beyond the muscularis propria or enlarged mesenteric or retroperitoneal lymph nodes I would like to review the remainder of the images The fi ndings are suspi-cious for a polyp malignancy I would ensure a staging

CT was performed At my institution, I would refer the patient for a same-day endoscopy examination and discuss this further at the multidisciplinary meeting

A 70-year-old man presents with a history of weight

loss (Figs 1.5.1 and 1.5.2).

Ideal Summary

These are selected images from a barium enema

series There is a short segment of irregular

circumfe-rential narrowing in the mid-transverse colon with an

“apple core” appearance (Figs 1.5.1 and 1.5.2, arrow)

Multiple diverticula are seen throughout the colon No

other lesions are seen in the remainder of the

visua-lised colon, and there is no proximal bowel dilatation

present to suggest bowel obstruction The most likely

diagnosis is colorectal carcinoma I would urgently

refer the patient to the surgical team and arrange a

staging CT examination

This is another case from a diﬀ erent patient, with CT

colonoscopy images (Figs 1.5.3 and 1.5.4).

This is an axial CT colonography image through the

abdomen with a three-dimensional intraluminal view

There is a polypoid mass in the right colon (Fig 1.5.3,

Trang 24

1.5 Colorectal Cancer

When assessing a stricture on a barium enema

series, look at:

• The site of the lesion

• The confi guration of the colon Has there been

previous surgery? Is the site of stricture at an

anastomosis?

• Is it in a watershed area? This raises possibility

of ischaemia

• Length Malignant strictures tend to be

shor-ter in length A longer length stricture may

be secondary to colitis, diverticulitis, or

ischaemia

• Is the stricture smooth or irregular?

• Are the ends of the stricture tapered or

shouldered?

• Assess for the presence of diverticula

In a primary colonic malignancy, look specifi cally

for a synchronous lesion (5%) and polyps (30%)

Always check for and comment on complications:

obstruction, perforation, or invasion into adjacent

organs

Assess the bones (on the correct window settings)

for metastases

On CT colonography, polyps that demonstrate the

fol-lowing morphology are suspicious for malignancy:

• Saddle-shaped lesions

• Polyps with a central depression

• Flat polyps: you are unlikely to have this in

the examination as it is a diﬃ cult lesion to

identify

There are no diﬀ erential diagnoses for the above

appearances However, the diﬀ erentials for a colonic

stricture include the following:

• This is most often seen in the sigmoid colon and

is usually a long (> 5 cm) segment of luminal rowing on a background of multiple diverticula

Extrinsic pathology

• There is smooth narrowing making obtuse angles with bowel wall, usually on the anti-mesenteric border of the colon

• Causes for this include endometriosis and rian malignancy

ova-Notes

Around 25% of colorectal carcinoma occurs in the moid colon, 20% in the rectum, and 15% in the trans-verse and ascending colon

sig-Regarding colorectal cancer screening in the UK:

Oﬀ ered to men and women aged 60 to 69 years every 2 years (extending up to 75 years in some areas)

If there is a positive faecal occult blood test, the individual is referred for colonoscopy

CT colonography is oﬀ ered when:

• Colonoscopy has been incomplete

• The patient is unfi t or unsuitable for colonoscopy

• The patient refuses colonoscopy

Oral contrast produces a “faecally tagged” study

Reconstruction of the CT data may be used to duce a three-dimensional volume- rendered intra-luminal image – “virtual endoscopy.”

pro-Bibliography

Dighe S, Swift I, Brown G CT staging of colon cancer Clin Radiol 2008;63(12):1372–1379

http://www.cancerscreening.nhs.uk/bowel/index.html (accessed Nov 2012)

Fig 1.5.4

Trang 25

Ideal Summary

This is a selected image from a barium

follow-through study There are several loops of abnormal

distal small bowel that are narrowed with

“cobble-stoning” and linear ulceration (Fig 1.6.1, arrow)

separated by shorter distended loops of ileum The

distal ileal loops show separation No defi nite fi stulas

are seen The appearances of the right colon are

sug-gestive of previous resection with a short segment of

narrowing at the ileocolonic anastomosis, although

contrast is seen within the colon The features are

consistent with active Crohn’s disease I would like to

assess the remainder of the series and any old fi lms

In a case with Crohn’s disease, comment on:

Location Although Crohn’s disease can occur

any-where along the gastrointestinal tract, there is

usually involvement of the terminal ileum with

small bowel involvement Describe where exactly the abnormalities are: proximal, mid, or distal small bowel, terminal ileum, or colon

Distribution Are there skip lesions, and are the abnormalities aymmetrical?

Luminal narrowing Is there any contrast stream of the narrowing; is there any pre-stenotic bowel dilatation?

Ulceration Are there aphthous ulcers that appear

as target lesions, linear ulcers that cross cular to the folds, fi ssuring, or cobble-stoning?

Fistula formation: enteroenteric, enterocolonic, or enterocutaneous

Bowel loop separation Obstruction: upstream bowel dilatation Evidence of previous operations Associations with Crohn’s disease: gallstones or sacroiliitis; comment if these are present on the barium image

No diﬀ erential diagnoses should be given in a case

of classic Crohn’s disease However, if there is only isolated terminal ileal abnormality, the following should be considered:

Lymphoma Tuberculosis “Backwash” ileitis with ulcerative colitis Ischaemia

Notes

There is an equal male to female distribution

Two peaks in incidence occur at ages 15 to 25 and

60 to 70 years

Small bowel follow-through was historically frequently used in the diagnosis of Crohn‘s disease, but this is now being replaced by CT and

• It may help estimate the extent of the disease and the length of remaining bowel

A 33-year-old man presents with abdominal bloating

and pain ( Fig 1.6.1).

Fig 1.6.1

Trang 26

100 consecutive patients examined by a barium infusion technique Clin Radiol 1980;31(5):597–603

Sinha R, Murphy P, Hawker P, Sanders S, Rajesh A, Verma R Role of MRI in Crohn’s disease Clin Radiol 2009;64(4):341–352

• It may be used to map small bowel fi stulas

associated with Crohn’s disease

Bibliography

Nolan DJ, Gourtsoyiannis NC Crohn’s disease of the small

intestine: a review of the radiological appearances in

1.6 Crohn’s Disease

Trang 27

1.7 Focal Nodular Hyperplasia

A 35-year-old asymptomatic woman (Fig 1.7.1).

Ideal Summary

This is a selected axial arterial-phase CT image

through the upper abdomen There is an enhancing

lesion in the left lobe of the liver, with a central

low-density scar and radiating septa (Fig 1.7.1, arrow)

There are no other liver lesions There are no features

to suggest liver cirrhosis The most likely diagnosis is

focal nodular hyperplasia (FNH), and other diﬀ

eren-tial diagnoses would include hepatic adenoma and

hepatic malignancy I would like to ask if there is any

venous-phase imaging to confi rm my diagnosis

This is the venous-phase CT image at the same level

Is there homogeneous or heterogeneous cement? Homogeneous lesions include FNH or smaller hepatic adenoma, while malignancy must

enhan-be excluded in heterogeneous enhancing lesions

Is there a scar? If so, it is more likely to be FNH or

fi brolamellar HCC

Is there background hepatic cirrhosis? If yes, HCC should be the primary diagnosis, unless there is strong evidence to suggest otherwise

What is the enhancement pattern?

• Arterial phase: FNH, hepatic adenoma, HCC, and neuroendocrine metastases are hyperen-hancing Other metastases are usually hypo-dense to liver

• Portal venous phase: hepatic adenoma and FNH are usually isodense compared with liver; malignancies are usually hypodense to liver

• Delayed phase: FNH and fi brolamellar HCC are isodense to liver; hepatic adenoma, HCC, and metastases are hypodense compared with liver

• Is there disruption to (haemorrhage of) the lesion? This favours hepatic adenoma or HCC

• Extrahepatic primary tumour: look specifi cally for this

The diagnostic possibilities for an arterial-phase enhancing lesion include:

Hepatic adenoma:

• Heterogeneous enhancement on arterial phase

• Variable enhancement on portal venous phase

• May be associated with disruption (haemorrhage)

Trang 28

Approximately 20% of FNHs are atypical.

• This includes telangiectatic FNH, which does not have a central scar, demonstrates persistent enhancement, and exhibits a high T1 and T2 signal on MRI

• However, atypical FNH still comprises biliary epithelium, and gadolinium BOPTA scanning may help in diﬀ erentiating

Ultrasound fi ndings:

• It is homogeneous and isoechoic to liver, with a hypoechoic central scar

• It may demonstrate a “spoke-wheel” pattern

on colour Doppler imaging

• Contrast-enhanced ultrasound demonstrates the classical “spoke-wheel” pattern and per-sisting enhancement into the late portove-nous phase

Fibrolamellar HCC:

• Usually very large and heterogeneous

• Presence of metastatic deposits in 70% of cases

Metastases:

• Usually multiple and in an older population

• Washout during the portal venous phase

“Flash” haemangioma: a lesion that fi lls rapidly

and not visibly from the periphery:

• Should continue to enhance on delayed-phase

imaging

Notes

Focal nodular hyperplasia is the second most

common benign liver tumour

There is usually only a single lesion in 80% of cases

Oral contraceptives do not cause FNH but have a

positive eﬀ ect on its growth

The lesion contains both hepatocytes and

non-communicating biliary structures

• Gadolinium BOPTA (gadobenate dimeglumine)

is excreted by the biliary epithelium

• It produces delayed and persistent enhancement

on MRI

• This may help diﬀ erentiate FNH from hepatic

adenoma, which will typically not enhance on

a hepatocyte-specifi c phase with gadolinium

BOPTA

1.7 Focal Nodular Hyperplasia

Trang 29

Ideal Summary

This is a plain abdominal fi lm I can see branching

lucencies projected over the liver centrally that are

likely biliary in origin (Fig 1.8.1, arrow) There is also

an ovoid lucency more laterally and may represent

gas within the gallbladder (Fig.1.8.1, arrowhead)

There are no dilated loops of small bowel, and the

colon is gas-fi lled and of normal calibre There is no

free gas I cannot see any focal calcifi cation that would

correspond to a gallstone The diﬀ erential diagnoses

for biliary gas include previous intervention and

gall-stone fi stula Are there any old fi lms available for

comparison? I would discuss the case with the

refer-ring team, and an abdominal CT may be necessary to

confi rm the diagnosis

These are two images from the abdominal CT nation (Figs 1.8.2 and 1.8.3).

exami-These are axial and coronal images of a venous-phase

CT through the abdomen A large, calcifi ed gallstone

is seen in the region of the proximal sigmoid colon, with surrounding fat stranding (Figs 1.8.2 and 1.8.3,

arrows) The colon and small bowel upstream of this are not distended There is no free gas On the coronal image, there is gas within the biliary system without

abdo-minal pain and vomiting (Fig 1.8.1).

Fig 1.8.1

Fig 1.8.2

Fig 1.8.3

Trang 30

Emphysematous cholecystitis: from gas-forming organisms within the biliary tract The patient will present with a septic clinical picture.

Gallstones can occasionally erode through the gallbladder wall and create a fi stulous tract, usu-ally into the duodenum, although the stomach and colon may be involved Gas may enter the biliary system via the fi stulous connection, giving rise to the branching linear lucencies

Large gallstones are often trapped at the ileocaecal valve, causing obstruction, but obstruction may occur at any point along the bowel

Bibliography

Chou JW, Hsu CH, Liao KF, et al Gallstone ileus: report of two cases and review of the literature World J Gastro-enterol 2007;13(8):1295–1298

Summerton SL, Hollander AC, Stassi J, Rosenberg HK, Carroll SF US case of the day Gallstone ileus Radiogra-phics 1995;15(2):493–495

overt biliary duct dilatation (Fig 1.8.3, arrowhead)

Some fl uid is seen around the gallbladder, but there

is no associated fat stranding The pancreas appears

unremarkable The fi ndings are in keeping with

a biliary fi stula secondary to a gallstone I would

inform the surgical team of these results

Rigler’s triad of small bowel obstruction, biliary gas,

and ectopic radiopaque gallstone is rarely seen, and

the candidate will usually be shown two of the three

signs on a plain abdominal fi lm When gas is

identi-fi ed within the liver, it is important to diﬀ erentiate

biliary gas from portal venous gas, as the

implica-tions for the patient are substantial Gas in the biliary

tree is typically near the hilum, carried there by the

fl ow of bile, in contradistinction to portal venous gas,

which is peripheral:

Aerobilia: recent endoscopic retrograde

cholangio-pancreatography (ERCP), sphincterotomy, biliary

stent, biliary surgery (such as hepaticojejunostomy)

Portal venous gas: ischaemic bowel, or

occasio-nally secondary to pneumatosis coli

Gas within the biliary system may arise from several

diﬀ erent causes:

Sphincterotomy: from previous ERCP

Surgical intervention: hepaticojejunostomy may

result in biliary gas

1.8 Gallstone Fistula

Trang 31

Ideal Summary

This is a selected image from a barium meal series

There is mucosal irregularity and nodularity, with

thickened folds involving the gastric antrum and

body, along the greater curvature (Fig 1.9.1, arrow)

The stomach does not distend in this region, and

contrast passes distally into the proximal duodenum

The gastro-oesophageal junction appears to be

spa-red There is no destructive bony abnormality The

appearances are in keeping with a diagnosis of

lini-tis plastica, most likely related to gastric carcinoma

I would like to review the rest of the barium series,

and I would recommend an endoscopy and a staging

CT examination

This is a CT image from the same patient ( Fig 1.9.2).

This is a selected axial image from a venous-

phase CT examination There is nodular thickening of

the gastric wall posteriorly at the level of the body of

the stomach (Fig 1.9.2, arrow) There is surrounding

fat stranding, but no defi nite peritoneal nodularity is

seen There is evidence of lymph node enlargement

around the aorta There are several enlarged lymph

of a gastrointestinal stromal tumour; if there

is marked diﬀ use mural thickening, consider lymphoma

Which part of the stomach is the abnormality centred on? If it involves the gastro-oesophageal junction, is there oesophageal dilatation; if it involves the pylorus or antrum, is there gastric outlet obstruction?

Is there evidence of direct invasion of the cent organs or abdominal wall? Look specifi cally for involvement of the aorta, adrenals, pancreas, spleen, and bowel

Is there metastatic disease or peritoneal disease? Look for peritoneal nodularity and thickening, best seen on CT coronal reformats

Trang 32

Although scirrhous gastric adenocarcinoma is the

most likely cause of linitis plastica, other less common

diﬀ erential diagnoses include:

Breast and lung metastases

Lymphoma

Radiotherapy

1.9 Gastric Carcinoma

Trang 33

evidence of distant disease, and I would refer the patient for discussion at a gastrointestinal multidis-ciplinary meeting.

These are images from another patient with an minal mass ( Figs 1.10.3 and 1.10.4).

abdo-These are selected postcontrast CT images through the abdomen There is a large, well-circumscribed mass taking up most of the abdominal cavity (Fig 1.10.3, arrow) The mass is centred on the left

upper quadrant and is causing mass eﬀ ect, displacing the bowel The mass itself is heterogeneous, being predominantly necrotic centrally with peripheral soft tissue density No focal calcifi cation is present Inferiorly, the mass appears to be lobulated There is ascites The bowel is mostly collapsed I cannot see any enlarged mesenteric lymph nodes I would like to

Ideal Summary

These are selected postcontrast CT images through

the upper abdomen There is an exophytic soft tissue

mass arising from the greater curve of the body of

the stomach (Figs 1.10.1 and 1.10.2, arrows) There

are multiple foci of calcifi cation within the mass,

and the adjacent stomach wall is slightly thickened

I cannot see any enlarged lymph nodes in the region

of the mass or around the coeliac axis There are no

focal intrahepatic lesions The most likely diﬀ

eren-tial is a gastrointestinal stromal cell tumour (GIST)

I would like to review the rest of the CT images for

Trang 34

Complications of masses:

• Compressive eﬀ ect: on bowel, vessels, ureters, and other abdominal structures

• Invasion of adjacent structures

Metastatic disease, look for evidence of a primary

or suggest that this may be the cause if the abdominal mass is indeterminate

intra-Diﬀ erential Diagnosis

Lymphoma: expect to see enlarged abdominal lymph nodes

Pancreatic pseudocyst: look for pancreatic calcifi cation as a marker for previous pancreatitis

Sarcoma arising from the retroperitoneum should

Aﬀ ects patients aged over 45 years

Occurs in the stomach in two-thirds of patients

GIST is associated with metastases to the liver and lungs, but not with regional lymph nodes If enlarged regional lymph nodes are present, GIST

is unlikely

Bibliography

Chourmouzi D, Sinakos E, Papalavrentios L, Akriviadis E, Drevelegas A Gastrointestinal stromal tumors: a pictorial review J Gastrointestin Liver Dis 2009;18(3):379–383

review the remainder of the CT images for evidence

of distant disease The imaging fi ndings are of a large

intra-abdominal mass arising from the left upper

quadrant The diﬀ erential diagnosis includes GIST

and lymphoma I would like to correlate this with

any previous images and the clinical history I would

take this further by oﬀ ering percutaneous biopsy of

the abnormal mass

When dealing with a large intra-abdominal mass,

consider the following:

Try to identify the area of the abdomen the mass

appears to be centred on or arising from Is the

mass arising from the pelvis? Are the bowel loops

pushed to one side? Are the retroperitoneal

struc-tures lifted anteriorly?

Once you have localised the mass, think about the

structures that lie there anatomically:

• Bowel If there is evidence of bowel

obstruc-tion, think of bowel malignancy

• Solid organs Look at the contour for distortion

• Lymph nodes Look for multiple enlarged

mas-ses with possible central necrosis

• Mesenchymal origin, that is, sarcomas These

are rare, but you need to consider this diagnosis

if you are uncertain about the origin of the mass

• Vascular Is the mass an aortic aneurysm? Look

closely at the vascular structures, particularly

if this is not an image from the arterial-phase

CT examination

Describe the mass in detail: size, homogeneity,

calcifi cation, enhancement, and relationship to

other structures

1.10 Gastrointestinal Stromal Cell Tumour

Trang 35

1.11 Cavernous Haemangioma

This is a venous-phase CT image of the same ent There now appears to be progressive peripheral enhancement (Fig.1.11.2, arrow) The most likely

pati-diagnosis is a giant hepatic haemangioma

Haemangiomas classically demonstrate centripetal

“fi lling in” on the venous and delayed phases However, the central scar does not enhance It is essential that venous-phase and/or a delayed-phase

CT image is obtained You cannot conclusively say that there is “fi lling in” on a single phase If there is uncertainty, ask for delayed-phase images

There are no diﬀ erential diagnoses for the above appearances However, where only a single phase

of imaging has been provided and it is unclear ther there is centripetal “fi lling in,” the possibility of

whe-an atypical haemwhe-angioma may be raised sive centrifugal [in to out] fi lling on the venous and delayed phases)

(progres-Notes

Giant hepatic haemangioma:

Is most common in postmenopausal women

Is defi ned as being larger than 10 cm Shows calcifi cation in only 10% of cases, this usu-ally being in the central scar

On MRI there is:

• Low T1 signal: the central scar has a markedly lower T1 signal

• High T2 signal: the central scar has a markedly higher T2 signal

• Sometimes there are low T2 signal internal septations

• Progressive centripetal fi lling on contrast- enhanced images

• A nonenhancing central scar

On ultrasound imaging:

• Giant haemangiomas often do not rate the classical increased refl ectivity

demonst-• Colour Doppler ultrasound is disappointing as

no fl ow is seen in the lesion

A 52-year-old woman presents with abdominal

dis-comfort (Fig 1.11.1).

Ideal Summary

This is a selected axial arterial-phase CT image through

the upper abdomen There is a large, irregularly shaped

lesion taking up the majority of the right lobe The

lesion is of intermediate density with central low

den-sity and no calcifi cation There is peripheral nodular

and discontinuous high density (Fig 1.11.1, arrow) I

can see no other lesions There is no CT evidence of

cir-rhosis The diﬀ erential diagnosis for these appearances

includes a giant haemangioma or malignancy I would

like to ask if any delayed imaging is available

This is a delayed CT image ( Fig 1.11.2).

Fig 1.11.1

Fig 1.11.2

Trang 36

1.11 Cavernous Haemangioma

• On contrast-enhanced ultrasound, the slow

peripheral globular enhancement and “infi

l-ling” is striking and often establishes the

diagnosis

Bibliography

Caseiro-Alves F, Brito J, Araujo AE, et al Liver haemangioma:

common and uncommon fi ndings and how to improve the diﬀ erential diagnosis Eur Radiol 2007;17(6):1544–1554

Trang 37

senting the “water lily” sign This is pathognomonic

of hydatid disease

This is a CT image from the same patient (Fig 1.12.3).

This is a selected arterial-phase axial image through the upper abdomen Two well-circumscribed, roun-ded low-density masses are seen within the liver Each of these masses has smaller lower density cysts along the periphery (Fig 1.12.3, arrows) There is no

abdo-minal pain (Fig 1.12.1).

Fig 1.12.1

Fig 1.12.2

Fig 1.12.3

Ideal Summary

This is a frontal chest radiograph of a woman There

is curvilinear calcifi cation (Fig 1.12.1, arrow) seen

below the right hemidiaphragm, which follows the

shape of the hemidiaphragm The right

hemidia-phragm is not greatly elevated, and the right lung

base is clear No similar abnormality is seen beneath

the left diaphragm, and there is no subdiaphragmatic

free gas

The curvilinear calcifi cation is most likely related to

the liver, and my primary diagnosis is a calcifi ed wall

of a cyst, with a hydatid cyst a consideration I would

like to compare this with any old fi lms and to confi rm

the diagnosis with an ultrasound examination

Trang 38

1.12 Hydatid Disease

intrahepatic duct dilatation The appearances are of

hydatid disease with daughter cysts I would like to

assess the remainder of the study to look for

compli-cations known to be associated with hydatid disease

This is an MR image from the same patient (Fig 1.12.4).

This is a T1-weighted contrast-enhanced MR image

of the liver Multiple cysts are seen within the upper

abdomen, with a large dominant cyst taking up most

of the left lobe of the liver The cysts are of T1 low

signal, and the daughter cysts of lower T1 signal

intensity (Fig 1.12.4, arrow) Several cysts are seen in

the left upper quadrant anterior to the spleen

with-out defi nable liver parenchyma seen around them

and may represent peritoneal seeding The imaging

fi ndings are characteristic of hydatid disease

Once a diagnosis of hydatid disease is reached, it is

important to assess the possible complications

ari-sing from this infection:

Cyst rupture can occur

Biliary communication This occurs in up to 90% of

cases Look for intraductal echogenic material on

ultrasound and high density on CT images

Infected cyst There will be low density around

the cyst with irregular or ill-defi ned walls and

possible stranding in the perihepatic fat If the

imaging fi ndings are suggestive of acute infl

am-mation, ask if there is a history of sepsis

Peritoneal seeding Check for peritoneal

nodula-rity There may be large, obvious peritoneal cystic

lesions If the picture is more subtle, it is easier to assess peritoneal surfaces on coronal reconstruc-tion of the CT examination

Check the lungs for pulmonary lesions and also for cyst rupture into the pleural cavity

The cyst itself may cause a mass eﬀ ect with upstream biliary duct dilatation or portal vein thrombosis

The appearance of a main cyst with daughter cysts and the “water lily” sign are pathognomonic

Notes

Hydatid disease is caused by the tapeworm

Echinococcus spp., but negative serology does not

exclude hydatid disease There is nearly always a tory of residence in an endemic area

his-Ultrasound fi ndings may vary, but include:

A double cyst wall: two hyperechoic walls rated by a hypoechoic layer

The presence of daughter cysts and the “water lily” sign (fl oating detached wall membranes), which are pathognomonic

Daughter cysts that may be mobile and whose location can change depending on the patient’s position

An anechoic cyst with hydatid “sand” that is dependent

MR imaging fi ndings:

Main cyst: usually T1 intermediate/T2 high signal

Daughter cysts: less T1 signal intensity than the main cyst, with high T2 signal

Rim: low T1 and T2 signal intensity due to its fi rous nature

Postcontrast: enhancement of the wall and septations

Bibliography

Doyle DJ, Hanbidge AE, O’Malley ME Imaging of hepatic infections Clin Radiol 2006;61(9):737–748 Pedrosa I, Saíz A, Arrazola J, Ferreirós J, Pedrosa CS Hydatid disease: radiologic and pathologic features and compli-cations Radiographics 2000;20(3):795–817

Fig 1.12.4

Trang 39

1.13 Liver Trauma

A 25-year-old man who was involved in a knife

stab-bing (Figs 1.13.1 and 1.13.2).

The patient was referred for angiography These are some images from the procedure (Figs 1.13.3 and 1.13.4).

These are selected images of a digital subtraction angiogram On the coeliac axis run, there is a small blush in the right anterior sectoral branch of the right hepatic artery (Fig 1.13.3, arrow) Selective

catheterisation of the right hepatic artery confi rms contrast extravasation (Fig 1.13.4, arrow) No evi-

dence of ongoing haemorrhage is seen on the embolisation site (Fig 1.13.4, arrowhead)

post-This is a CT image of a diﬀ erent patient, a 30-year-old man, following a road traﬃ c accident (Figs 1.13.5

and 1.13.6).

These are selected venous-phase axial CT ges through the upper abdomen I note the pre-sence of bilateral chest drains There is a linear

ima-Fig 1.13.1

Fig 1.13.2

Fig 1.13.4 Fig 1.13.3

Ideal Summary

These are selected axial images through the upper

abdomen in both arterial and venous phases Linear

high density is seen in the right lobe on the arterial

phase (Fig 1.13.1, arrow), with pooling of contrast

on the venous phase (Fig 1.13.2, arrow) This is

surrounded by low density on the venous phase,

and there is perihepatic haematoma No

intraperi-toneal free gas is seen The kidneys and pancreas

appear unremarkable I would discuss this patient’s

case urgently with the surgical team and

interven-tional radiologist

Trang 40

1.13 Liver Trauma

laceration through the liver between the right

and left lobes that extends up to the inferior vena

cava (Fig 1.13.5, arrow) This is associated with

a large subcapsular haematoma of mixed density

(Fig 1.13.5, arrowhead) On the second axial image,

there is a rounded enhancing opacity adjacent to the

laceration (Fig 1.13.6, arrow), which is suspicious for

contrast extravasation, but I would like to confi rm

this by comparing it with the arterial-phase scan No

intraperitoneal free gas is seen I would like to review

the chest and remainder of the abdomen to identify

any other injuries I would then urgently discuss the

case with the interventional radiologist for

angiogra-phy with a view to embolisation

This is an image from the angiographic procedure

(Fig 1.13.7).

This is an angiographic image of a coeliac axis run A

rounded opacity can be seen arising from a right lobe

hepatic artery, representing ongoing haemorrhage

(Fig 1.13.7, arrow) No other sites of bleeding are seen.

Features of liver trauma to identify include:

Intraperitoneal blood and/or subcapsular toma, with eﬀ acement of the underlying liver parenchyma

The shape and extent of the laceration: linear, branching, or stellate? Does it extend through to the opposite margin or involve the porta hepatis?

Evidence of ongoing haemorrhage: the presence

of contrast extravasation on the arterial phase, with pooling of contrast on the venous phase Lacerations that involve the bare area of the liver, which may be complicated by retroperitoneal haemorrhage

Always check adjacent organs for injury and peritoneal free gas as a marker for bowel injury

intra-Diﬀ erential Diagnosis

There are no diﬀ erential diagnoses for these imaging appearances

Notes

The use of CT imaging before an interventional cedure is now an accepted imaging strategy with the advent of “fast” scanning times and the location of the CT scanner close to the emergency room and angiographic suites Intervention is rarely perfor-med without CT imaging as this localises the site and extent of the injury and allows targeted intervention

Định dạng
Số trang	146
Dung lượng	4,29 MB